Seriously, try killing one necromorph with that thing on zealot difficulty. You could empty the whole clip to its head and use the second ability with it not even falling to the ground. Google the rivet gun and you'll see the forums of how under powered it is.

Completely agree about the Rivet Gun. I used it only 1 time to kill a Necromorph and when I got to the very next Store Location I swapped it out and haven't used it since. I wish we were able to at least sell the gun at the Store for Credits because it's pretty much useless to me.